Title

Author

Year of Publication

2007

Document Type

Dissertation

College

Arts and Sciences

Department

Psychology

First Advisor

Charles R. Carlson

Abstract

This study examined the emotional and physiological differences between masticatory muscle pain patients and age, height, and weight matched pain-free controls. Physiological activation and emotional reactivity were assessed in the 22 muscle pain patients and 23 pain-free controls during a baseline rest period, while discussing a personally relevant stressor, and during a post-stressor recovery period. Physiological activity was assessed through the use of the frequency domain heart rate variability indices. Activity in the high frequency heart rate variability range is an index of parasympathetic activity while activity in the low frequency heart rate variability range is an index of both sympathetic and parasympathetic activity (Akselrod, 1981). The muscle pain patients showed significantly more physiological activation during both the baseline rest and the post-stressor recovery periods. These physiological differences were quantified by higher low frequency heart rate variability and lower high frequency heart rate variability during these study periods. This pattern of higher activation was also present in the report of emotional reactivity in the muscle pain patients. The emotional and physiological differences between the groups across study periods were more pronounced in muscle pain patients who reported a traumatic life experience. These results provide evidence of physiological activation and emotional responding in masticatory muscle pain patients that differentiates them from matched pain-free controls. The use of HRV indices to measure physiological functioning quantifies the degree of sympathetic and parasympathetic activation. Study results suggest the use of these HRV indices will improve understanding of the role that excitatory and inhibitory mechanisms play in the onset and maintenance of chronic masticatory muscle pain conditions.